DNA sequencing is an integral component of modern molecular biology essential to many biomedical research scientists on a regular basis. This application request for funding of a new ABI DNA analyzer model 3100 to be installed and managed by the established departmental Core Lab in the Department of Molecular and Experimental Medicine (MEM), The Scripps Research Institute (TSRI). MEM is currently one of the larger of the nine departments within TSRI and is composed of over 55 active research faculty members and more than 90 postdoctoral fellows and research associates. The MEM Core Laboratory, established about 12 years ago, has been managed by the P.I. and two technicians. The DNA sequencing service provided by the MEM Core is available primarily for, but not restricted to, the MEM department which is located in a 20-month old new building across the North Torrey Pines Road on the east side of the TSRI campus. Over the past 6 years, the Core's DNA sequencing service has been made available to investigators associated with the Multipurpose Arthritis and Musculoskeletal Disease Center (MAMDC) for San Diego through funding from NIAMS, NIH. As the MAMDC program is terminating at NIAMS, continuing funding for the sequencing service has been submitted under the new NIAMS program Rheumatic Diseases Core Centers (RDCC). The proposed RDCC will provide sequencing service, through the MEM Core to investigators involved in studies of rheumatic diseases in UCSD and other institutions in San Diego. The proposed ABI 3100 DNA analyzer exemplifies second-generation application of capillary electrophoresis for sequence analysis. Recent advances in the DNA analyzer technology include speed, throughput, and labor saving as a result of the enhancement in automation, all of which are highly desirable for the MEM Core sequencing service. The new analyzer will largely replace the current ABI 377 sequencer with the exception for special DNA sequencing needs in a core facility environment. The annual maintenance cost for the proposed ABI 3100 will be supported by departmental funds. This instrument will be an important asset to serve well in furthering the progress of many NIH- funded research in the MEM Department and the proposed RDCC.